For centuries people are wondering, what is dream? During the time of early civilization, people thought that dream is a medium between the world of earth and the Gods. In fact, Greeks and Romans thought that dreams have various prophetic powers. Many people showed their curious interest in interpreting scientific reasons behind dreams. By the end of 19th century, Sigmund Freud and Carl Jung put forth some popular theories of dreams. The theory of Freud expressed notion of repressed longing. It is an idea which says that dreaming allows us to sort unsettled, repressed wishes. Carl Jung believed that dreams have psychological importance.
Along with the advancement in technologies, there were developments of other theories. One of the prominent neuro biological theories of dreaming is activation synthesis hypothesis”. It says that the dreams don’t have any meaning in particular. The theory shows that the dreams are nothing but the electrical brain impulses that pull random thoughts and images from our memories. It is humans who after waking up put their efforts to make sense of what they see and create stories out of it. Indirect experimental evidence shows that other mammals such as cats also dreams. Evolutionary psychologists gave theory that dreams serve a purpose.
Threat simulation theory shows dreaming as an ancient biological defense mechanism which provides an advantage of evolution. It has capacity of simulating repeatedly potential threatening events. Thus, dream enhances the neuro-cognitive mechanisms which are required for efficient threat perception and avoidance. Over all these years, various theories are available to find the mystery behind human dreams.
The new research shows the strong relationship between dreams and our memories. At the University of Rome, Cristina Marzo and her colleagues succeeded in explaining about the way human remember their dreams. The scientists find a signature pattern of brain waves behind the successful dream. To carry out this research, Italian research team invited 65 students and asked them to spend 2 consecutive nights in research laboratory. For the 1st night, students were left to sleep so that they can get comfortable in the sound-proof and temperature-control room. On the 2nd night, scientist measured the brain waves of students while they were sleeping. There are four types of brain waves- delta, alpha, theta and beta. All four of them have different oscillating electrical voltage. All four of them form electroencephalography(EEG).
At various steep stages, scientists used this technology to measure brain waves of students. Students were waked up at particular time and they were supposed to fill diary regarding their dream. They were even supposed to mention whether they had a dream or not and if they remember their dream. People who waked after REM sleep and who had low frequency theta waves in frontal lobes remember their dreams. The research helped in finding out that the mechanism during dreaming and while constructing and retrieving memory is same.
Also the other theory using the latest MRI techniques suggests that there exist a link between emotion and dreams. Dreams are helpful as they help us in processing our emotion by encoding and constructing memories of them. It is not necessary that what we see in our dreams should be real. But the emotions attach to those dreams are real. Dream strip the emotion by creating a memory. In this way, emotion is no longer active. Therefore, it plays an important role especially when we don’t process our emotions, importantly the negative ones, this high ups personal worry and anxiety.
Dreams help us in regulating traffic on the bridge which links our experiences with our emotions and memories.